Gyroscopic apparatus



July 17, 1928.

A. CHESSIN GYROSCOPIC APPARATUS Filed Dec. 23, 1919 WITNESSES:

Patented July 1 7, 1928.

UNITED STATES PATENT OFFICE.

ALEXANDER GHESSIN, OF NEW YORK, N. Y.

eYnoscorIo APPARATUS.

Application filed December 23, 1919. Serial No. 346,921.

gravity, will retain its direction in absolute space, i. e. in the spacein which our earth.

1s moving. The axis of such a gyroscope, if set in the meridian of theplace of observation, will accordingly, move away from this meridian asthe earth rotates. Gyroscopic compasses, therefore, must be providedwith means for driving the gyro axis towards the meridian. In presentday devices, this so called precession of the gyroscope is effectedeither directly, or indirectly, by means of a gravity torque. It is'animportant and distinctivefeature of my invention that no such use ismade of gravity and that the means for driving or spinning the gyroscopeconstitute also means for causing it to precess towards the meridian.

Another important feature of my invention is its simplicity, because allthe elements needed to make it function as a compass are combined in themeans for spinning the gyroscope.

A further and new feature of importance is the motor, which providesboth the power for spinning the gyroscope and the power for making itprecess.

The use of magnetic pull, in lieu of gravity, torause precession, formsalso a new and useful feature. Other novel features will appear from thedetailed description of my invention.

Before passing to this description, let it he noted that only parts ofthe complete structure in each case are shown in the draw mgs, namely,the parts which directly embody the new features. Thus, although the.

specifications and drawings, as shown, have reference, in particular, tomarine compasses. the gimbal rings, in which the described parts wouldbe suspended in the well known manner, are omitted so as not tocomplicate the drawings. Likewise, no invention being claimed of themanner of frictionless suspension used for the specified and describedparts, various forms of such spension are either briefly indicated, ormerely assumed, again, in order not to complicate the drawings withirrelevant matter. This method of omitting well known devices from thespecifications and drawings is adhered to t roughout.

' It may be well, also, to define at the outset certain terms used inthe description of my invention. One of these terms is axis of thedriving torque. A torque being equivalent to a couple of forces, theaxis of the torque is the axis of this equivalent couple. The torqueitself is represented by a line of definite length and direction, and wemay speak of its components just as we speak of the components of aforce. Another term, viz: normally, used in reference to horizontal orvertical axes, relates to positions under, conditions of perfectequilibrium,i. e. when the structure suspended in gimbals is notswinging, and the gyroaxis itself is at rest. Finally, while I avoid theuse of the word precession in general, I have retained it, in preferenceto the word turning, for the movement of the gyroscope towards themeridian, because the use of the term precession in this connection hasbecome familiar in the art.

Referring to the accompanying drawings:

' Figure 1 is a vertical cross section of a gyroscopic deviceillustrating one of the preferred forms of my invention. The gyroscope,in this case, is the rotor of an. electric motor and it can tiltrelatively to the stator, which forms a art of the casing shown in crosssection, t e casing itself being suspended in a torsionless manner,although the mechanism which makes the suspension torsionless is notshown. 1

Figure 2 is a horizontal cross section of the same device.

Figure 3 is a front elevation of another form of my invention, in'whichthe gyroscope is made to spin by the impact of a jet of liquid or gas.

Figure 4 is a detail of this second form of my invention, being a topview of the spinning body.

Figure 5 is a diagram of the forces acting in this, and in thepreceding, cases, the diagram on the right being for the first, thepreferred, form, and the diagram on-the left for the second form. l

Figure 6 is a front elevation, and Figure 7 a side elevation, of a thirdform of my invention, in which any method of spinning the gyroscope maybe used.

Figure 8 is a front elevation of still another form of my invention. Africtionless suspension is assumed in this and in the preceding forms,although only ordinary bearings are shown in the drawings.

Certain portions of Figure 3 are shown in cross section to betterillustrate the operation for that form of my invention.

In the following description and claims,

' specific names are necessarily used for identifying parts, but theyare intended to be as generic in their application to similar parts asthe art will permit.

When the meridian is mentioned, it is always in reference to themeridian of the place of observation, or, more correctly, in referenceto the meridian at the center of the roscope.

Re erring particularly to Figures 1 and 2, 1 is a cross section of acasing which contains an induction motor;2 is the stator of thisinduction motor and is an integral part of the casing with which it isconnected by means of extensions 3 which are arranged to leave openspaces for the swinging of the ring 4. This ring 4 is rotatably mountedin the casing at 5 and carries the rotor 6 of the induction motor, therotor itself constituting the gyroscope in this case. The

casing 1 is suspended in a torsionless manner, indicateddiagrammatically by the wire 7, from a frame not shown in the drawing,and it is assumed that this latter frame is connected with the bodycarrying the whole apparatus by means of gimbals in the well knownmanner.

The principle of operation of this device as a compass will now beexplained. Let the gyroscope axle, i. e. the axle of the rotor, be sethorizontally, away from the meridian. As the Earth rotates, thegyroscope developes a tendency to tilt relatively to the horizon, as isindicated on Figure 1 by the dotted lines. The magnetic pull between thestator and the rotor of the induction motor will draw the rotor backinto the position indicated on Figure 1 by the full lines. In. ac-

' the meridian,

cordance with the well known action of gyroscopes, this will effect aturning motion, or precession, of the rotor, together with the casing,about the vertical towards the meridian. This action is reversed whenthe gyroscope axle passes to the other side of and the gyroscope willoscillate back and forth about this meridian.

The forces developed by the tendency of the rotor to tilt relatively tothe stator are shown diagrammatically on the right side of Figure 5, forthe upper halfpf the rotor when the rotor is inclined in a directionopposite to the one indicated on Figure 1. symmetrically disposedforces, with directions reversed, act on the lower half of the rotor. Itwill be observed that the resultant f of the magnetic pull gives acomponent P which drives or spins the rotor and a component P whichdraws the rotor back from its inclined position. It will be furtherobserved that the point of application of this resultant of the magneticpull is off the equatorial plane of the rotor. Therefore, besides thetorque which causes the rotor to turn with the ring 4 in the bearings 5,which we may call the precessional torque, a torque is developed aboutthe line M of Figure 1, and the vertical component of this latter torqueis such as to oppose the swinging motion of the gyroscope about thevertical. This opposition is maximum at the moment when the gyroscopepasses the meridian (because at this moment the axle of the rotor makesits maximum angle with the horizon), and it is minimum when thegyroscope reaches the end of a precessional swing (because at such timesthe gyroscope axle is horizontal). The result is that the oscillationsof the gyroscope about the meridian are damped, i. e. the swingssteadily diminish in amplitude.

Referring now particularly to Figure 3, the casing l of the preferredform is replaced by the frame 8, having a hollow base:

9 which rests on an air cushion inside the base 10 of a frame 11, theframe 8 being rotatably mounted in the frame 11 on pivots 12. The air,which is supplied by means of a flexible tube 13, enters the base 10 ofthe frame 11 through perforations centrally disposed and is allowedpartly to escape through the open space 14 and part1 to enter the hollowbase 9 through perforations in its bottom, whence the air is led intothe nozzles 15 through ducts in the pil-- lars 16 of the frame 8. Thering 4 of the preferred form is here replaced bythc ring 17 rotatablymounted in the frame 8 at 18. The ring 17 carries the spinning body 19rotatably mounted in this ring at 20. The spinning body is in the formof a wheel having curved blades 21. The principle of operation in. thisdevice is similar to that of my preferred form. lVhen the axis of spinof the gyroscope wheel is inclined to the horizon, the jet, of air fromthe nozzle 15 strikes the blades 21 off their centers, forcing thewheels axle back into a horizontal position, which, again, results inprecession of the body about the tions about the meridian. The diagramof forces, shown on the left of Figure 5, in which f now represents thecomponent of the air impulse normal to the blade curve, againillustrates the fact that a force f is produced for driving the wheeland a force f for causing it to return to the vertical vertical andoscilla-,

Ilia

cation of the force f being off the equatorial plane of the wheel,atorque is produced about the vertical which effects a damping of thebodys oscillations about the meridian.

Passing on to Figure: 6 and 7, the upper and lower circular discs 22,connected by the uprights .23, constitute a frame, corresponding to theframe 8 of the preceding case. This frame is rotatably mounted on pivots24 in another frame 25, corresponding to the frame 11 of the precedingcase. While only ordinary pivot bearings are shown, any one of the knowntypes of mounting for frictionless rotation about the vertical isassumed and would be adopted in practice. A frame 26 is rotatablymounted in the uprights 23 at 27, and carries a gyroscope28 pivoted inthe frame 26 at 29. The two discs 22 carry each a permanent or aneleotromagnet 30. The frame 26 has portions 31 of soft iron which areaffected by the magnetic pull of the magnets 30 when the gyroscope tiltsrelatively to the horizon.

Figure 8 illustrates a form of my invention wherein centrifugal forcesare utilized to arrive at the same refults as in my preferred form. Twogyroscopes 37 are shown, connected by means of universal joints 38 attheir respective centers with the driving axles of two motors 33 and 34,these motors being jointly mounted in the frame 32 for. free rotationabout a vertical axis. The two motors rotate in opposite direction sothat they exercise no gyroscopic effect. The two gyroscopes 37, however,spin in the same direction. This is effected by means of reversing gearsenclosed in the casing 35 which is attached to one of the motors, acounterweight 36 being attached to the other motor to preserve balance.The action of centrifugal forces, when the gyroscopes are inclined tothe driving axles of the motors, is to draw the gyroscopes intopositions wherein their axes of spin coincide with the axes of thedriving axles of the motors. The result is in every way similar to thatobserved and explained for my preferred and for my second forms ofinvention.

Itshould be observed that, owing to the damping feature of my invention,as in other gyroc'opic compasses having this feature, the gyro-axis,when at rest, is not exactly horizontal, nor exactly in the meridian,but makes a very small angle with the meridian and is slightly inclinedto the horizon. There are numerous ways to compensate for the slightdeficetaon from the exact NS position, and various means are known tothe art for making the compass card read dead-beat. Compen ating devicesinclude other corrections, such as, for instance, corrections forlatitude changes. These and similar corrective means are omitted from myspecifications, drawings and claims, forreasons already stated in thepreamble to the description, but it is to be under'tood that they areomitted without prejudice to the appended claims, wherein reference ismade to a definite position relatively to the meridian, rather than tothe meridian itself, having in mind the slight angle which thegyro-axis, without the above mentioned corrections, makes with themeridian, in its position of rest relatively to the Earth. It

will further be understood that various omissions, substitutions andchanges in the form and in the details of my device and in its operationmay be made by those skilled in the art, without departing from thespirit of the invention.

Having duly described my claim:

1. A gyroscopic compass comprising a framesuspended for rotation, abouta vertical axis, a gyroscope mounted in said frame to tilt about ahorizontal axis, and means to spin said gyroscope, which means exert atorque on the gyroscope about said horizontal axis to resist the tiltingthereof.

2. An apparatus comprising a frame mounted for rotation about an axis, agyroscope mounted in said frame to tilt about a second axis, and meansto spin said gyro scope, which means exert .a torque on thegyroscope'about said second axis to resist the tilting thereof.

3. A gyroscopic compass comprising a frame, means whereby said frame issuspended for rotation about a vertical axis, a gyro fcope pivotallymounted in said frame to tilt about a horizontal axis at right angles toits axis of spin, and electro-magnetic means to spin said gyroscope andresist-the tilting thereof. I

4. The combination with a gyroscope mounted to turn about an axis otherthan invention, I

its axis of spin, of means to spin said gyroscope, which means exert atorque on said gyroscope about said other axis to resist turnin thereofabout sald other axis.

5. The combination with a gyroscope having substantially three degreesof rotational freedom, of means to spin said gyroscope, which meansexert a torque on said gyroscope about an axis other than the axis ofspin, to restrain the rotational freedom of the gyroscope about saidother axis.

6. The combination with a. gyroscope hav ing substantially three degreesof rotational freedom, of means for spinning said gyroscop'ev about oneaxis, said means exerting a torque onthe gyroscope having componentsabout two other axes to restrain rotational freedom of the gyroscopeabout said two other axes. g

7. The combination with a. gyroscope, of means whereby said gyroscope ismounte to tilt about an axis and to spin about another axis, ofelectromagnetic means to spin said gyroscope and resist tilting aboutsaid other axis. r

8. In a gyroscopic compass, a frame mounted for free rotation about avertical axis, a second frame mounted in the first frame to turn about ahorizontal axis, a gyroscope mounted in the second frame to spin aboutan'axis perpendicular to'said hori-' zontal axis, and means to spinsaidgyroscope,

said means exerting a torque about said horizontal axis to resistturning of said second frame;

9. In gyroscopic compass, a structure mounted for free rotation about'avertical axis and comprising a frame, a second frame pivoted in thefirst frame to turn about a horizontal axis, and a motor composed of astator and a rotor, said stator being integral \With said first frameand said rotor being pivoted in said second frame to spin about an axisperpendicular to said horizontal axis, said motor comprising means forexerting a torque about'said horizontal axis to resist turning of saidsecond frame.

'10. in a gyroscopic compass, a frame, means whereby said frame issuspended for free rotation about a vertical axis, a second framepivoted in the first frame to rotate about a horizontal axis, agyroscope pivoted in said second frame to spin about a normallyhorizontal axis perpendicular to said first mentioned horizontal axis,and electromagnetic means to spin said gyroscope and resist deviation ofits axis of spin from a horizontal position.

11. A gyroscopic compass comprising a frame, means whereby said frame issuspended for free rotation about a vertical axis, a gyroscope mountedin said frame to freely turn about a horizontal axis perpendicular toits axis of spin when the gyroscope is not spinning, and means forexerting a torque a out said horizontal axis to resist turning of saidgyroscope thereon when the gyroscope spins.

' 12. A gyroscopic apparatus comprising a frame, means whereby saidframe is mounted for free rotation about an axis, a gyroscope mounted insaid frame to freely turn about a second axis other than 't-s axis ofspin when the gyroscope is not spinning, and means for exerting a torqueabout said second axis to resist turning of said gyroscope thereon whenthe gyroscope spins.

" 13. A gyroscopic comp-ass comprising a frame suspended for freerotation about a vertical axis, a, gyroscope mounted in said frame totilt about a horizontal axis perpendicular to its axis of spin, andmeans to resist the-tilting of said gyroscope within a predeterminedangle, which means become inoperative upon the tilting of said gyroscopeexceeding said predetermined angle.

14. A gyroscopic apparatus comprising a frame mounted for free rotationabout an axis, a gyroscope mounted in said frame to turn about a secondaxis other than its axis of spin, and means to resist turning about saidsecond axis Within a predetermined angle, which/means become inoperativeupon the tilting of said gyroscope exceeding said predetermined angle.

15. An apparatus comprising a motor mounted for rotation about an axisand composed of a stator and a rotor which may turn relatively to oneanother about a second axis perpendicular to the rotor axle, said motorbeing adapted to resist relative turning of the stator and the rotorabout said second axis within an angle not exceeding a predeterminedangle.

16. An apparatus comprising a frame mounted for rotation about an axis,and an electric motor, the stator of said motor being attached to saidframe, and the rotor being mounted therein to tilt relatively to saidstator.

17. An apparatus comprising a frame mounted for rotation about avertical axis, and an electric motor, the stator of said motor beingattached to said frame, and the rotor being mounted therein to tiltabout a horizontal axis.

18. In a gyroscopic comp-ass, means comprising a motor suspended forrotation about a vertical axis and composed of a stator and a rotorwhich may tilt relatively to one another about a horizontal axis, forproducing a torque upon a relative tilt therebetween, said torque havingcomponents about both of said axes.

19. In a gyroscopic apparatus, means com prising a motor mounted forrotation about an axis and composed ofa stator and a rotor which. may.tiltrelatively to one another about a second axis, for producing atorque upon a relative t-ilt therebetween, having a component about saidsecond axis.

ALEXANDER CHESS-IN.

